This invention relates generally to dry cleaning machines and dry cleaning processes and, more particularly, to devices and related methods which reclaim dry cleaning solvent from dry cleaning machines.
Dry cleaning machines typically cleanse clothing with a dry cleaning fluid which normally includes water and a solvent, such as perchlorethylene ("perc.") or trichlorethylene. Since dry cleaning solvents tend to be toxic to the environment and pose waste disposal problems, dry cleaning machines normally employ a process which substantially recirculates the dry cleaning fluid. Commonly, the fluid is substantially vaporized during the dry cleaning process and recycled in an effort to recover a substantial amount of the solvent that would otherwise be released into the environment. At the end of such dry cleaning processes, the dry cleaning fluid in its vaporous state is condensed back into a liquid and flows through a fluid separator. The separator then separates the water present in the fluid from the solvent and the now separated water is characteristically disposed of in a drainage system or by other suitable means. These processes may also employ filtration devices which filter out solvent from the vapor that is otherwise exhausted from a given dry cleaning machine into the environment. A dry cleaning machine that employs a separator is described in U.S. Pat. No. 3,977,218 to Guido Zucchini and is incorporated by this reference. Certain dry cleaning machines also have central vacuum systems which remove waste water from the dry cleaning machine and transfer it to a suitable receptacle for disposal. Thus, existing dry cleaning machines tend to reduce the amount of solvent that is freely discharged into the environment.
More recently, however, governmental environmental protection agencies and others have begun to focus on the waste water or other waste fluid which is discharged from separators and other appropriate receptacles and into the environment. In this regard, it has been discovered that, despite the use of separators and the like, the waste water still often contains a residual concentration of solvent that is unacceptably high. Certain environmental laws or regulations promulgated, for example, now require that the concentration of residual solvent in the water so discharged cannot exceed four or five parts per billion (ppb.) Consequently, a number of dry cleaning establishments now face a significant waste disposal problem, since they cannot dispose of the water from separators in existing drainage systems without violating these recent environmental laws or regulations. Additionally, a number of businesses which specialize in the transportation and disposal of hazardous waste will not collect the contaminated water from separators in dry cleaning machines. Alternatively, even if waste disposal businesses do dispose of the water, dry cleaning businesses must absorb the added expense of such disposal.
It should, therefore, be appreciated that there exists a definite need for a device and method for reclaiming residual dry cleaning solvent from the waste water that is to be emptied from a fluid separator or other suitable receptacle of a dry cleaning machine and which reclaims the solvent in a manner which is cost effective, environmentally sound, and addresses recently promulgated environmental laws and regulations.